Systems and methods for external detection of misconfigured systems

ABSTRACT

A computer-implemented method is provided for external detection of a vulnerable system coupled to a communication network. The method can include measuring communication traffic on the communication network to identify one or more domain names, which in turn can originate from server systems in the communication network. The method can further include identifying the domain names based on metadata from the domain names and/or the measured communication traffic, where each domain name has an associated property indicative of its vulnerability. The method can further include determining whether any one (or more) of the domain names is registered at a domain name registry and, if the domain name is not registered, registering the domain name.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No. 17/014,495, filed Sep. 8, 2020, which is a continuation of U.S. patent application Ser. No. 15/954,921, filed Apr. 17, 2018, now U.S. Pat. No. 10,812,520, the contents of each of which are hereby incorporated by reference herein in their entirety.

TECHNICAL FIELD

The following disclosure is directed to methods and systems for detecting vulnerable systems, and, more specifically, methods and systems for detecting vulnerable systems based on domain name properties.

BACKGROUND

In an age of increased cybercrime and varied cybersecurity efforts, detecting vulnerabilities before, or within real-time, a security flaw is exploited can be a true business advantage to companies, governments, institutions, and individuals. In many instances, there are benign but misconfigured systems having these security flaws that become targets for parties with nefarious intentions. Every day, seemingly endless types and numbers of malignant actors exploit security flaws for the purpose of theft (both monetary and of data), espionage, frustration (e.g., denial of service attacks and mass spamming), terrorism, and more. However, the resources necessary to get ahead of these potential threats can be astounding and unfeasible.

SUMMARY

Domain names on the Internet can be a specific source of security flaws and, often, speed in detecting exploitation of domain names becomes crucial to overcoming attacks. To track and detect security flaws in real time, or near real time, systems and methods can monitor communication traffic and extract metadata related to the traffic and/or domain names to detect vulnerable systems.

In accordance with an embodiment of the disclosure, a computer-implemented method is provided for external detection of a vulnerable system coupled to a communication network. The method can include measuring communication traffic on the communication network to identify one or more domain names, which in turn can originate from server systems in the communication network. The method can further include identifying the domain names based on metadata from the domain names and/or the measured communication traffic, where each domain name has an associated property indicative of its vulnerability. The method can further include determining whether any one (or more) of the domain names is registered at a domain name registry and, if the domain name is not registered, registering the domain name.

Embodiments of the methods can include one or more of the following features. Domain names having the property indicative of vulnerability can be: (i) an unregistered domain name, (ii) a malfunctioning domain name, (iii) an abandoned domain name, and/or (iv) an algorithm-generated domain name. The vulnerable system can be a malware-infected server system and/or , a misconfigured server system.

In some embodiments, the metadata can include a geographical location associated with each domain name. If so, the registration of the domain name based on the extracted metadata includes registering the domain name based on a high frequency of domain names having a property indicative of vulnerability in a particular geographical location. The method can further include associating the registered domain name with a server system configured to monitor communication traffic to the registered domain name, and, in some instances, detecting the vulnerable system associated with the registered domain name. Measuring communication traffic to each of the plurality of domain names can further include receiving communication traffic data from one or more Internet service providers (ISP), comparing relative magnitude of communication traffic to an expected amount of traffic, and/or measuring a frequency of communication traffic to the domain name.

In accordance with another embodiment of the disclosure, a system including one or more computer systems programmed to perform operations is provided. The operations include measuring communication traffic in the communication network to identify one or more domain names, where the communication traffic originates from server systems in the communication network. The domain names are based on metadata from (i) the domain names and/or (ii) the measured communication traffic, where each domain name has an associated property indicative of its vulnerability. The operations further include determining whether any one (or more) of the domain names is registered at a domain name registry, and if the domain name is not registered, registering the domain name.

Embodiments of the systems can include one or more of the following features. Domain names having the property indicative of vulnerability can be: (i) an unregistered domain name, (ii) a malfunctioning domain name, (iii) an abandoned domain name, and/or (iv) an algorithm-generated domain name. The vulnerable system can be a malware-infected server system and/or, a misconfigured server system.

In some embodiments, the metadata can include a geographical location associated with each domain name. If so, the registration of the domain name based on the extracted metadata includes registering the domain name based on a high frequency of domain names having a property indicative of vulnerability in a particular geographical location. The method can further include associating the registered domain name with a server system configured to monitor communication traffic to the registered domain name, and, in some instances, detecting the vulnerable system associated with the registered domain name. Measuring communication traffic to each of the plurality of domain names can further include receiving communication traffic data from one or more Internet service providers (ISP), comparing relative magnitude of communication traffic to an expected amount of traffic, and/or measuring a frequency of communication traffic to the domain name.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B are flowcharts of exemplary embodiments of methods for detecting vulnerable systems coupled to a communication network.

FIG. 2 is a diagram of an exemplary embodiment of a system for detecting vulnerable systems coupled to a communication network.

FIG. 3 is a block diagram of an example computer system that may be used in implementing the systems and methods described herein.

DETAILED DESCRIPTION

Disclosed herein are exemplary embodiments of systems and methods for detecting vulnerable systems in communication networks. These vulnerable systems can include one or more computing systems, one or more server systems, or other networked systems. In many instances, vulnerable systems are associated with domain names on the Internet. “Domain names,” as used herein, may refer to registered or unregistered names, addresses, and/or links to a resource on the Internet.

Some domain names may be associated with vulnerable resources. In some embodiments, an algorithm may generate links to domain names that are not registered or generated in error. For example, an algorithm that links to “google.com” may incorrectly generate links such as “gooooogle.com” or “goggle.com.” In another embodiment, an application developer may register a domain name for a legitimate service or business. If the business associated with the domain name closes, and the domain name is abandoned, the domain name may become expired or “dropped” from the registry. If so, the registry may delete the domain name (de-register) and the domain name may become available to another party. In another embodiment, a registered domain name may be associated with a misconfigured system. For example, the misconfigured system may be operating with security flaws that open the system to security risks. In another embodiment, parties acting with nefarious intentions (criminals or criminal groups, malignant state-sponsored actors, etc.) may register domain names for their own purposes (e.g., malware, botnets, etc.). In another embodiment, an anti-virus software program may try to contact domain names repeatedly based on some acquired misinformation. If so, that domain name will have repeat incoming traffic. Examples of detection of botnets is discussed in CONDENSER: A Graph-Based Approach for Detecting Botnets, by Camelo et al., and in Botnet Cluster Identification (Master Thesis), by Pedro Camelo, each of which are incorporated herein by reference.

The below described exemplary systems and methods are configured to identify such domain names, and in some embodiments, identify one or more vulnerable systems associated with such domain names. For the purpose of clarity and conciseness, the methods and systems of FIGS. 1A-3 are discussed below together.

Detection Systems and Methods

FIGS. 1A-1B are flowcharts of exemplary embodiments of methods for detecting vulnerable systems coupled to a communication network. FIG. 2 is a diagram of an exemplary embodiment of an environment 200 in which a system for detecting vulnerable systems coupled to, or part of, a communication network operates.

In step 102, the detection system 202 measures communication traffic in the communication network to identify a plurality of domain names of interest. The communication traffic can be originating from one or more external (separate from the system 200) server systems 204 in the communication network. External server systems can include company servers, desktop computers, Internet of things (IoT) devices, mobile devices, or any other device on external networks. In some embodiments, the communication traffic can be provided by one or more Internet service providers (ISPs). Many ISPs track communication traffic to domain names for standard business purposes. However, the monitoring and/or measuring of communication traffic is typically associated with large amounts of data. Thus, in some embodiments, metadata related to the measured communication traffic may be extracted from the communication traffic in the interest of efficiency. Meta data can include geographical location of the communication traffic, frequency of the communication traffic, magnitude of the communication traffic, aggregated counters of a number of unique Internet Protocol (IP) addresses per country, a number of events observed per period (e.g., every hour), a ratio between unique IPs versus a sum of a portion or all communication traffic. Efficiency may be crucial in some instances where a domain name may be associated with a flawed, but important Internet resource that is vulnerable to malware. In some embodiments, the ISPs can provide a list of domain names that are the subject of network traffic. This list of domain names can be analyzed to identify those that may be addresses for vulnerable systems. In some embodiments, the detection of nonexistent domain names being contacted by a group of devices does not necessarily map to malicious behavior. In some cases, the behavior can be mapped to a control failure associated with a software or service dependent on those domains. When that control failure occurs, the affected devices can become vulnerable to malicious actors that can potentially acquire the nonexistent domains and gain control over the associated devices.

In step 104, the detection system 202 identifies one or more domain names (1 through N) that each are vulnerable with regard to some property or attribute. For example, the domain name can have the following conditions associated therewith: (i) an unregistered domain name, (ii) a malfunctioning domain name, (iii) an abandoned domain name, and/or (iv) an algorithm-generated domain name. In some embodiments, the domain names can be identified based on the metadata extracted from the measured communication traffic and/or the domain names themselves. For example, a domain name may be identified based on statistical anomalies regarding traffic emanating from or directed to the domain name, or suspicious IP header information extracted from packets directed to the domain name. Examples include identification of a group of systems or devices attempting to contact nonexistent domain names at a given frequency, from a given set of geographies, and/or using specific protocols and/or payloads. This group of devices interacting with one or more domains, using a similar pattern and/or frequency, may be associated with automated traffic generated by malware, or may be caused by mis-configurations of machine-to-machine communication.

One important advantage to extracting metadata of the communication traffic is that much (or all) of the data from the traffic and associated parameters do not have to be stored. Instead, a detection system 202 can include a streaming server 206 that executes queries on the data in real time or near real time. In some embodiments, the extracted metadata can include geographical information related to the communication traffic. If so, for example, the detection system 202 can detect a group of domain names associated with a particular geography (such a city or region of a country) with significant incoming traffic. In some embodiments, the relative magnitude of traffic (or “cluster” of traffic) may be measured to identify domain names. For example, if one or a handful of parties are pinging “gogle.com,” it is likely a mistake (such as mistyping). However, if thousands of parties are pinging the same domain name “gogle.com,” the detection system 202 may identify that domain name as a candidate for registration. Thus, the measured traffic may be compared against an expected amount of traffic for the purpose of detection. Measures of expected amounts of traffic may be available from the ISPs themselves or other services. In another embodiment, the frequency of the traffic may be measured. An anomalous pattern of contacting a domain name may signify a vulnerability. For example, if the system 202 detects a group of devices periodically attempting to contact a domain, or group of domains, at a given frequency (for example, each hour), such a detection can be indicative of automated malicious traffic.

In some embodiments, the traffic data and/or data regarding the domain names may be stored and analyzed by accessing the storage 208. By determining one or more domain names having a vulnerable property or attribute, the detection system can ultimately detect and/or identify one or more vulnerable systems 210 associated with the domain name.

In step 106, the detection system 202 is configured to determine whether each domain name is registered at a domain name registry. In step 108, if the domain name is not registered, then the system 202 is configured to register the domain name. Once registered, in step 110, the system 202 can associate the registered domain name with a server system 212 configured to monitor communication traffic to the registered domain name. The server system 212 may be controlled by the detection system 202. In step 112, the detection system 202 can identify and/or detect one or more vulnerable systems associated with the registered domain name. Once the domain name (e.g., domain name 2 of FIG. 2 ) has been acquired and configured on the server system 212, the vulnerable system(s) 210 will typically contact the domain on the server system 212 using a specific network protocol and payload. Inspecting the network request by the vulnerable system 210 allows the detection system 202 to associate the vulnerable system(s) with malicious or other anomalous behavior that triggered the domain communication.

Computer-Based implementations

In some examples, some or all of the processing described above can be carried out on a personal computing device, on one or more centralized computing devices, or via cloud-based processing by one or more servers. In some examples, some types of processing occur on one device and other types of processing occur on another device. In some examples, some or all of the data described above can be stored on a personal computing device, in data storage hosted on one or more centralized computing devices, or via cloud-based storage. In some examples, some data are stored in one location and other data are stored in another location. In some examples, quantum computing can be used. In some examples, functional programming languages can be used. In some examples, electrical memory, such as flash-based memory, can be used.

FIG. 3 is a block diagram of an example computer system 300 that may be used in implementing the technology described in this document. General-purpose computers, network appliances, mobile devices, or other electronic systems may also include at least portions of the system 300. The system 300 includes a processor 310, a memory 320, a storage device 330, and an input/output device 340. Each of the components 310, 320, 330, and 340 may be interconnected, for example, using a system bus 350. The processor 310 is capable of processing instructions for execution within the system 300. In some implementations, the processor 310 is a single-threaded processor. In some implementations, the processor 310 is a multi-threaded processor. The processor 310 is capable of processing instructions stored in the memory 320 or on the storage device 330.

The memory 320 stores information within the system 300. In some implementations, the memory 320 is a non-transitory computer-readable medium. In some implementations, the memory 320 is a volatile memory unit. In some implementations, the memory 320 is a non-volatile memory unit.

The storage device 330 is capable of providing mass storage for the system 300. In some implementations, the storage device 330 is a non-transitory computer-readable medium. In various different implementations, the storage device 330 may include, for example, a hard disk device, an optical disk device, a solid-date drive, a flash drive, or some other large capacity storage device. For example, the storage device may store long-term data (e.g., database data, file system data, etc.). The input/output device 340 provides input/output operations for the system 300. In some implementations, the input/output device 340 may include one or more of a network interface devices, e.g., an Ethernet card, a serial communication device, e.g., an RS-232 port, and/or a wireless interface device, e.g., an 802.11 card, a 3G wireless modem, or a 4G wireless modem. In some implementations, the input/output device may include driver devices configured to receive input data and send output data to other input/output devices, e.g., keyboard, printer and display devices 360. In some examples, mobile computing devices, mobile communication devices, and other devices may be used.

In some implementations, at least a portion of the approaches described above may be realized by instructions that upon execution cause one or more processing devices to carry out the processes and functions described above. Such instructions may include, for example, interpreted instructions such as script instructions, or executable code, or other instructions stored in a non-transitory computer readable medium. The storage device 330 may be implemented in a distributed way over a network, such as a server farm or a set of widely distributed servers, or may be implemented in a single computing device.

Although an example processing system has been described in FIG. 3 , embodiments of the subject matter, functional operations and processes described in this specification can be implemented in other types of digital electronic circuitry, in tangibly-embodied computer software or firmware, in computer hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. Embodiments of the subject matter described in this specification can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a tangible nonvolatile program carrier for execution by, or to control the operation of, data processing apparatus. Alternatively or in addition, the program instructions can be encoded on an artificially generated propagated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal that is generated to encode information for transmission to suitable receiver apparatus for execution by a data processing apparatus. The computer storage medium can be a machine-readable storage device, a machine-readable storage substrate, a random or serial access memory device, or a combination of one or more of them.

The term “system” may encompass all kinds of apparatus, devices, and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. A processing system may include special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit). A processing system may include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of them.

A computer program (which may also be referred to or described as a program, software, a software application, a module, a software module, a script, or code) can be written in any form of programming language, including compiled or interpreted languages, or declarative or procedural languages, and it can be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network.

The processes and logic flows described in this specification can be performed by one or more programmable computers executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by, and apparatus can also be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

Computers suitable for the execution of a computer program can include, by way of example, general or special purpose microprocessors or both, or any other kind of central processing unit. Generally, a central processing unit will receive instructions and data from a read-only memory or a random access memory or both. A computer generally includes a central processing unit for performing or executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Moreover, a computer can be embedded in another device, e.g., a mobile telephone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a Global Positioning System (GPS) receiver, or a portable storage device (e.g., a universal serial bus (USB) flash drive), to name just a few.

Computer readable media suitable for storing computer program instructions and data include all forms of nonvolatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry.

To provide for interaction with a user, embodiments of the subject matter described in this specification can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. In addition, a computer can interact with a user by sending documents to and receiving documents from a device that is used by the user; for example, by sending web pages to a web browser on a user's user device in response to requests received from the web browser.

Embodiments of the subject matter described in this specification can be implemented in a computing system that includes a back end component, e.g., as a data server, or that includes a middleware component, e.g., an application server, or that includes a front end component, e.g., a client computer having a graphical user interface or a Web browser through which a user can interact with an implementation of the subject matter described in this specification, or any combination of one or more such back end, middleware, or front end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include a local area network (“LAN”) and a wide area network (“WAN”), e.g., the Internet.

The computing system can include clients and servers. A client and server are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

While this specification contains many specific implementation details, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Moreover, although features may be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub-combination or variation of a sub-combination.

Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system components in the embodiments described above should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

Particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. For example, the actions recited in the claims can be performed in a different order and still achieve desirable results. As one example, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous. Other steps or stages may be provided, or steps or stages may be eliminated, from the described processes. Accordingly, other implementations are within the scope of the following claims.

Terminology

The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

The term “approximately”, the phrase “approximately equal to”, and other similar phrases, as used in the specification and the claims (e.g., “X has a value of approximately Y” or “X is approximately equal to Y”), should be understood to mean that one value (X) is within a predetermined range of another value (Y). The predetermined range may be plus or minus 20%, 10%, 5%, 3%, 1%, 0.1%, or less than 0.1%, unless otherwise indicated.

The indefinite articles “a” and “an,” as used in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” The phrase “and/or,” as used in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with “and/or” should be construed in the same fashion, i.e., “one or more” of the elements so conjoined. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, a reference to “A and/or B”, when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A only (optionally including elements other than B); in another embodiment, to B only (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

As used in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of” or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.

As used in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

The use of “including,” “comprising,” “having,” “containing,” “involving,” and variations thereof, is meant to encompass the items listed thereafter and additional items.

Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed. Ordinal terms are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term), to distinguish the claim elements. 

What is claimed is:
 1. A computer-implemented method for external detection of a vulnerable system, the vulnerable system coupled to a communication network based on domain name properties, the method comprising: receiving communication traffic in the communication network to identify at least one domain name associated with a vulnerable system, the communication traffic originating from at least one server system in the communication network; executing queries on the communication traffic to extract metadata while monitoring the communication traffic; identifying the domain name having an associated property indicative of vulnerability of the domain name based on the metadata, wherein the domain name having the associated property indicative of vulnerability comprises a domain name associated with malicious activity; and if the domain name is not registered with a domain name registry, registering the domain name and detecting the vulnerable system associated with the malicious activity.
 2. The method of claim 1, wherein the vulnerable system is a malware-infected server system.
 3. The method of claim 1, wherein the vulnerable system is a misconfigured server system.
 4. The method of claim 1, wherein the metadata further comprises a geographical location associated with each domain name.
 5. The method of claim 1, further comprising: associating the registered domain name with a server system configured to monitor communication traffic to the registered domain name.
 6. The method of claim 1, wherein each domain name is selected from the group consisting of: (i) an unregistered domain name, (ii) a misconfigured domain name, (iii) an abandoned domain name, and (iv) an algorithm-generated domain name.
 7. The method of claim 1, wherein receiving communication traffic data comprises: receiving communication traffic data from at least one Internet Service Provider (ISP).
 8. The method of claim 1, further comprising: comparing a relative magnitude of communication traffic to an expected amount of communication traffic.
 9. The method of claim 1, wherein receiving communication traffic data comprises: measuring a frequency of communication traffic to the domain name.
 10. The method of claim 1, wherein the metadata comprises at least one of the group consisting of: (a) geographical location of the communication traffic, (b) frequency of the communication traffic, (c) magnitude of the communication traffic, (d) aggregated counters of a number of unique Internet Protocol (IP) addresses per country, € a number of events observed per period, and (f) a ratio of unique IP addresses to a sum of a portion of the communication traffic.
 11. A system for external detection of a vulnerable system coupled to a communication network, the system comprising: at least one computer systems programmed to perform operations comprising: receiving communication traffic in the communication network to identify at least one domain name associated with a vulnerable system, the communication traffic originating from at least one server system in the communication network; executing queries on the communication traffic to extract metadata while monitoring the communication traffic; identifying the domain name having an associated property indicative of vulnerability of the domain name based on the metadata, wherein the domain name having the associated property indicative of vulnerability comprises a domain name associated with malicious activity; and if the domain name is not registered with a domain name registry, registering the domain name and detecting the vulnerable system associated with the malicious activity.
 12. The system of claim 11, wherein the vulnerable system is a malware-infected server system.
 13. The system of claim 11, wherein the vulnerable system is a misconfigured server system.
 14. The system of claim 11, wherein the operations further comprise: associating the registered domain name with a server system configured to monitor communication traffic to the registered domain name.
 15. The system of claim 11, wherein each domain name is selected from the group consisting of: (i) an unregistered domain name, (ii) a misconfigured domain name, (iii) an abandoned domain name, and (iv) an algorithm-generated domain name.
 16. The system of claim 11, wherein receiving communication traffic data comprises: receiving communication traffic data from at least one Internet Service Provider (ISP).
 17. The system of claim 11, wherein the operations further comprise: comparing a relative magnitude of communication traffic to an expected amount of communication traffic.
 18. The system of claim 11, wherein receiving communication traffic data comprises: measuring a frequency of communication traffic to the domain name.
 19. The system of claim 11, wherein the metadata comprises at least one of the group consisting of: (a) geographical location of the communication traffic, (b) frequency of the communication traffic, (c) magnitude of the communication traffic, (d) aggregated counters of a number of unique Internet Protocol (IP) addresses per country, (e) a number of events observed per period, and (f) a ratio of unique IP addresses to a sum of a portion of the communication traffic. 